Mini function generator circuit using ICL8038

This is the Mini function generator circuit using ICL8038 IC-number. (Precision Waveform Generator/ Voltage Controlled Oscillator) It will generate output 3 the waveform, include Sine wave signal,the triangle, and square wave signals. The output of this circuit is quite realistic in the waveform. And we will suggest a 2 model include (1.) the basic model (2.) the improved performance model,we can customize even more. If you interested, don’t wait. Let’s see it below!

The Basic circuit diagram function generator using ICL8038

Basic Circuit Of Function Generator Using ICL8038
Figure 1 The basic circuit of function generator using ICL8038

The Basic characteristics of the circuit with a few components, it consists of the VR1-potentiometer, the R1-resistors and the C1-capacitors to determined frequency output. We can use the below formula to calculate the frequency output as follows.

The Frequency output (f)
= 0.15/(VR1+R1)C1…….(1)

First, If the waveform is not symmetrical. The output of IC1 can be modified as follows. Secondly, we connect the 500 ohms-resistors across pin 4 and VR1. Then, connect pin 5 with VR1 just done.
The first circuit will be cheaper. It has low performance.
We recommend to create a second circuit for real use. It add slightly parts.

The components list
Resistors size 1/4W 5%
VR1____10K Single potentiometer
C1______See in text
IC1___ICL8038___Precision Waveform Generator/ Voltage Controlled Oscillator
Socket IC, The Universal PCB Board, and other etc.

How to builds
You can build this circuit on universal PCB board on Figure 2. the wiring, and various components can see carefully. For the devices has various polarity should be careful in the assembly circuit. They include the electrolytic capacitors, potentiometer, resistors and Pin of the IC is not an error.

Figure 2 the components layout of the basic circuit.

The Model is developed of function generator by ICL8038

But if the model is developed as in Figure 3. May have to invest a lot. Which device has the additional duty is different. But the important point is to make circuit more stablea and Adjustment to the desired waveform.

Figure 3 the circuit diagram of the model is developed.

After that We come to understand the equipment to do it. Started at D1, R1 and R2 is the control output of signal has a symmetric or duty cycle at 50%. The VR1 and VR2 to adjust the waveform at output is a distortion of the original signal. The VR3 is used to select the desired frequency at output, and Finally is VR4 is used to obtain the highest frequency there. For the C1 of both circuit Be used to determine the frequency of each district vary as Table 2.

Table 2 the value of capacitor-C1 that use in each frequency range of the function generators

Frequency range _____ C1 value
1Hz – 100Hz______1uF

The all capacitors using to withstand voltage at 25 volts, And If you want this machine provides output from lowest to highest by Without changing C1, It’s not hard, just to pin 10 of IC1 with various values of C1 in to selector switches. You are now a Mini function generator that has output of 3 model. Them to informally

How to builds this projects
We can builds this circuit as Figure 4 as the components layout on the universal PCB board. Which looks like building project by mins ago project.

Figure 4 the components layouts of this projects.

The components list.

Resistors size 1/4W 5%
VR1,VR2___100K(B) Dual potentiometer
VR3______10K(B) Single potentiometer
C1_________See text
C2_________0.1uF(104) 50V Ceramic
D1____ 1N914 or 1N4148__ 75V 150mA Diodes
IC1___ICL8038___Precision Waveform Generator/ Voltage Controlled Oscillator
Socket IC 14 pin, Universal PCB board.


  1. pratibha January 31, 2015 Reply
  2. Peter October 23, 2016 Reply

Add a Comment

Your email address will not be published. Required fields are marked *